Munetaka Yagyuu (柳生宗崇 | やぎゅうむねたか | Yagyū Munetaka) is a dark and mysterious figure throughout the anime. This older gentleman, with an injured eye and scar, dresses in Western-style clothing, carries a katana, and rides a motorcycle as he disappears from the city. He works from the shadows, at first using Marie Claire as his servant to observe Tendou Kodzunu's progress in disrupting the Ryumyaku (Dragon Vein). The black cat that Claire keeps is his familiar.
Yagyuu is, in fact, the prime antagonist, and his ultimate goal, though vague, is to throw society into chaos and conflict; he seeks a new world order to exalt himself. The first opportunity, he uses the revival of the Kodzunu clan, allowing Tendou to do as he pleases and merely bearing witness to the events. Later, after besting Tougo Narutaki in a private duel, he turns to manipulating the Martial Fist; he uses them to kill innocent people, including putting a hit on those fighting the demons. He seems to stay one step ahead of the protagonists, already knowing that Ryuuji Yashiro exists and locating the Black Dragon, Yin to the Golden Dragon.
Besides his extreme knowledge and proficient martial arts, his supernaturnal powers are unmatched. Yagyuu even granted Tendou Kodzunu and Renji Magatsu their demonic arcane abilities, though both were overcome by the Dark Arts and turned into demons themselves. When Ryuuji finally awakens to his powers as a Vessel , Yagyuu is also able to invoke the Dark Arts in a Unification Ritual, thoroughly absorbing the boy's newfound powers.
His past is an enigma, and the only personal details known is that his birth day is July 25th. However, his evil powers were seen throughout Japan's history. Munetaka Yagyuu was present over 150 year earlier, during the Edo period, manipulating the characters fighting the Tokugawa shogunate - including Tendou Kodzunu's ancestors.
Yagyuu was once sealed away by earlier Stars of Fate, including Genma Hiyuu, who sacrificed his own life to save his newborn son, Tatsuma . But Yagyuu eventually broke free of his imprisonment, his Dark Arts reborn, and continues his quest for domination.
When he's efforts prove fruitless, and Tatsuma Hiyuu stronger than he anticipated, Yagyuu flees the battlefield for China. According to videogame sources, there is the possibility that is his homeland, or at least where he draws his powers.
In the manga, Munetaka Yagyuu is actually another high school student, a senior at Tenryuuin High in Shinjukuku. The young man has long red hair, with a scar across his face. He is the leader of the Gehou cult, using the Kidou-shuu to keep watch over the supernatural activity in Tokyo, seeking to find the one capable of thwarting all his demons - and the Yang to the Yin Dragon he keeps close, "Kaosu". He is still a dark character, the prime antagonist throughout, controlling others from the shadows.
- The character Munetaka Yagyuu is also featured in the prequel video game Tokyo Majin Gakuen: Gehouchou, the Bakumatsu-based game in the franchise. His involvment is much the same, and he kills off many of the main characters for failing him in the end.
- His arc with Genma Hiyuu, Ryuuzan Arai, and the others in the older generation was given a spin-off video game Tokyo Majin Gakuen Oboro-Kitan. More of his past is revealed, and he is shown as the leader of a rebellious group of Hakka-han (中国の「客家」) people of Han Chinese descent.